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Questions and Answers on Avian Influenza
Commission Européenne - MEMO/05/142 28/04/2005
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Brussels, 28 April 2005
What is Avian Influenza?
Avian Influenza is a virulent and highly contagious viral disease which occurs in poultry and other birds. It was first identified in Italy in the early 1900s. There are various strains of the avian influenza virus, with the high pathogenic strains having almost 100% fatality rates. Wild birds are often carriers of the low pathogenic strains of the virus without showing any symptoms, and contact of domestic flocks with wild migratory birds has been at the origin of many epidemics in poultry. Avian influenza can occasionally spread to humans and other animals, usually following direct contact with infected birds.
What has been the recent situation of avian influenza outbreaks?
In recent years the poultry industry worldwide has suffered serious damage due to avian flu epidemics. Since 2003, the particularly virulent H5N1 strain of the disease has caused more than 125 million birds to die or be destroyed in South-East Asia. Avian flu is still endemic in this region of the world and eradication is proving extremely difficult. Outbreaks of avian flu also occurred in the USA, Canada and South Africa in 2004.
In the EU, recent major outbreaks of avian flu occurred in Italy (1999-2000) and the Netherlands, with incidences in Belgium and Germany (2003). The outbreak in the Netherlands led to the destruction of around 30 million birds and direct economic costs of more than €150 million.
What threats does avian influenza pose to human health?
In most cases, avian influenza viruses do not infect humans. However, these viruses have the tendency to mutate and may occasionally spread to other animals and to humans. In particular, there have been cases of humans becoming infected with certain highly pathogenic subtypes of the avian flu virus due to direct contact with diseased birds. The 2003 outbreak of the disease in the Netherlands resulted in 1 human death and numerous milder human infections. In South-East Asia, around 50 people have died from avian flu since the current outbreak began. A major concern now is that a possible mutation or genetic change of the virus circulating in Asia could lead to the avian flu virus transforming into a new human strain of influenza capable of human-to-human transmission. The European Commission and EU Member States are working continually on pandemic influenza planning and response measures in case of such an eventuality.
Why is the Commission proposing new measures for avian influenza?
The proposed Directive on measures for the control of avian influenza aims to update EU measures based on lessons learned from recent epidemics and new scientific knowledge on how the disease spreads and risks to human health. Current EU legislation on avian influenza control is laid down in Council Directive 92/40/EEC. This Directive only establishes control measures against the so-called “highly pathogenic” avian influenza viruses, those causing major disease outbreaks in poultry and that may also occasionally infect humans. However, there is now evidence that these highly pathogenic viruses actually originate from the so-called “low-pathogenic” avian influenza viruses as a result of virus mutation. In order to prevent major avian influenza outbreaks, the new legislation would also establish compulsory surveillance and control measures against the low pathogenic avian influenza viruses that can be transmitted to domestic poultry from wild birds such as ducks and geese. The low pathogenic viruses cannot be eradicated from wild birds, but the infection of domestic poultry can be effectively controlled and virus mutation into the highly pathogenic forms can be prevented. The aim of the new legislation is to ensure that the most appropriate surveillance and prevention measures against avian flu are in place and that the health risks, economic costs and the negative impact on society in the event of an outbreak are minimised. The previous Directive will be repealed when the new Directive is adopted.
Why is surveillance necessary and how will be applied?
Early detection of low pathogenic viruses in domestic poultry is a key factor to prevent highly pathogenic form of disease. In the last years avian influenza surveillance has already been implemented in all Member States, but the new legislation will be in place will make this more systematic, eg Member States will have to implement national surveillance plans taking into consideration risk factors such as the possibility of contact of domestic poultry with wild birds, risk factors associated with different poultry species, the density of poultry farms, etc. Surveillance will also be carried out on wild birds to ensure that new knowledge is gained on the risks posed by these birds. Based on the results obtained, the Commission and the Member States will regularly revise the surveillance plans to increase their effectiveness.
Which measures will be applied to low pathogenic avian influenza?
To prevent the spread of the disease to other farms, Member States will have to ensure that the poultry are not moved from the farms where low pathogenic avian influenza has been detected. Birds from the affected farms must be either killed and destroyed (“stamping out”) or slaughtered normally. The virus is rapidly inactivated by heat, which means that there is zero risk to human health from cooked poultry meat. All available information suggests that even if eaten raw, the risk to human health posed by the consumption of poultry meat from birds infected with low pathogenic strains is probably negligible. However, under certain circumstances stamping-out may still be a necessary measure, as the movement of poultry from the farm where they are kept to the slaughterhouse may cause the virus to spread from farm to farm.
How will the new measures be funded?
According to an impact assessment carried out when preparing the Directive, the additional cost of the new measures to the EU budget have been estimated at €3-8 million a year. This will be financed by the EU Veterinary Fund. However, projections based on the frequency and cost of past outbreaks of Avian Influenza show that the additional cost to the EU budget should be more than recuperated by savings related to reduced risks of future epidemics, which have in the past been very costly to control (with the EU co-financing control measures). Moreover, some of the control measures envisaged in the new legislation, such as vaccination, should diminish the size of any future avian influenza outbreaks, resulting in further savings.
Why is the EU now more keen on vaccination than before?
Recent outbreaks of highly pathogenic avian influenza in the EU and elsewhere have shown us how devastating this disease can be. All means to prevent future disasters have been carefully considered, including vaccination. The decision on whether or not to use vaccination is still not easy, but there is increasing experience indicating that it can be a useful tool, for example where domestic birds are exposed to the virus among wild birds. The use of vaccination will always be strictly monitored and the EU rules will require that vaccinated birds can be differentiated from infected birds. This is very important both for disease control and for trade purposes. The vaccination and monitoring system proposed in the new Directive will be managed so that restrictions on trade in poultry and poultry products from the vaccinated areas can be minimised. Eventual restrictions on trade will be decided on a case-by-case basis. In any case, restrictions will only be applied to the specific regions using vaccination, or even compartments within those regions. All areas of the EU not using vaccination will be able to continue to trade normally.
If Italy is a test case for the new vaccination approach, what does the current outbreak there say about the future policy on vaccination?
In northern Italy, a new approach to vaccination (the so called DIVA strategy) has been tested over the past four years in an area at high risk of disease due to frequent virus incursions from wild birds into poultry farms, one of which led to a major epidemic in 1999/2000. The DIVA strategy is accompanied by very strict surveillance in the vaccination area, so that virus introduction can be detected at an early stage and vaccinated birds can be differentiated from the infected ones.
Broadly speaking, the results obtained in Italy with the DIVA strategy were satisfactory and they were well accepted also at the international level. Nevertheless, this strategy was not able to prevent the very recent low pathogenic avian influenza outbreak which has occurred in Lombardy (April 2005). However, the strict surveillance led to the early detection of the virus and the vaccination programme probably contributed to containing it. These are key elements to prevent the virus from mutating into its highly pathogenic form.
The Commission proposal takes into account all experiences gained related to disease control and provides for a more flexible approach to vaccination. However, it must be noted that there are still many constraints to vaccination and that this tool is not a panacea to solve all problems.
What is the EU doing to help Asia tackle the current outbreak there?
The ongoing outbreak of highly pathogenic Avian Influenza in Asia has lead to the death or the killing and destruction of over 125 million birds, economic losses estimated at €8-12 billion and the death of around 50 people. Furthermore, there are fears that this particular virus strain may eventually lead to a human flu pandemic.
The World Health Organisation (WHO), the Food and Agriculture Organization of the United Nations (FAO) and the World Animal Health Organisation (OIE) have called for decisive action by governments to help the countries affected to limit the scale of the bird flu outbreak and so also reduce the risk for public health in Asia.
In coordination with the relevant international organisations, the European Commission has already provided some emergency technical and financial support to the concerned countries, Vietnam in particular, to help to control the disease in poultry and other birds and prevent as much as possible the spread of the virus to humans. However, the eradication of avian flu from Asia cannot be considered a realistic short-term objective and adequate planning and co-ordination of future actions and control measures is essential.
The FAO is currently finalising a regional master plan including a road map and time frame, within which framework the concerned countries can than draft their own country plans. This FAO master plan and the country plans will be carefully studied as soon as available, in view of possible support by the Commission.
How would our new legislation help prevent serious outbreaks such as the one currently seen in Asia?
Avian flu viruses circulate worldwide in migratory waterfowl, such as ducks and geese. However, at that stage the viruses are not able to cause serious disease; they are defined as low pathogenic viruses. Only after the spread from wild birds to domestic poultry and circulation in the poultry populations, the low pathogenic viruses may mutate into highly pathogenic viruses, like the one that is causing major disease problems in parts of Asia and that is also affecting humans.
The new proposed legislation will require EU Member States to introduce and reinforce surveillance and control measures against the low-pathogenic viruses, aiming in particular at preventing virus circulation in domestic poultry, so that virus mutation and highly pathogenic forms of disease are prevented.
Which Asian countries are currently blocked for what exports?
The Commission has undertaken a number of actions to protect the EU from disease introduction from Asia. Imports of live birds and risky poultry products such as fresh poultry meat and untreated feathers from the concerned countries have been prohibited. However, this ban does not concern heat-treated poultry meat, as the heat-treatment (70 degrees) destroys the avian influenza virus.
The disease situation in Asia is regularly reviewed at the Standing Committee on the Food Chain and Animal Health, where the safeguard measures taken are updated as appropriate. At present, the import ban concerns Cambodia, China including Hong Kong, Indonesia, Laos, Malaysia, North Korea, Pakistan, Thailand and Vietnam.